1. Technical Field
The present invention relates to electric arc furnaces (EAFs) and more specifically, to a monitoring system and method therefore that provides substantially real-time data about the operation of the electric arc furnace to a local user and which is transmitted over a global computer network to a remote secured database, from which historical reports may be generated as desired.
2. Background Art
In the steel industry, electric arc furnaces (EAFs) are used to melt metals and other ingredients to form steel. The heat needed to melt the metals is generated by passing current through one or more carbon bodies, commonly referred to as graphite electrodes, and forming an arc between the electrode(s) and the metals in the furnace.
In conventionally operated EAFs, the operator periodically collects raw data about different operational aspects of the furnace, such as operating electrical current levels, cumulative oxygen used, temperature of the molten steel, etc.
This raw data is typically stored on a local programmable logic computer (PLC) and accumulates quickly. The raw data is collected at a faster rate than the operator can review and assess it. Sometimes, the raw data is printed out. At the time the operator starts his or her review of the data, the data is often out-dated, leaving the operator only the ability to prepare reports based on the historical operation of the furnace. As a result, although the operator has access to lots of information, it is not as useful to him or her as it could be since it does not allow the operator to view the data in substantially real-time so as to adjust the furnace operation in an effort to maximize the furnace's performance and, for example, minimize electrode consumption.
U.S. Pat. No. 5,539,768 to Kracich (the '768 patent) discloses an electric arc furnace electrode consumption analyzer. In known electric arc furnaces, the furnace includes at least one electrode projecting into a furnace for containing a charge to be heated and an electrode support structure for moving the electrode toward and away from the charge. Specifically, the '768 patent teaches the use of a sensor for detecting the position of electrode support structure from an initial position. A processor calculates the travel distance and the rate of electrode consumption and triggers an alarm at certain predetermined operational parameters. While this device is useful to improve electrode performance because it provides substantially real-time data that the operator may use to make decisions about the furnace operation, it is disadvantageous because it limits the operator's decision based on travel distance alone, when electrode consumption is generally a function of many variables.
U.S. Pat. No. 5,099,438 to Gulden, Jr. et al. teaches the use of a method for “on-line” monitoring and control of the performance of an electric arc furnace. Here, the term “on-line” does not refer to any global computer network, but rather is used as a synonym for “direct.” The '438 patent teaches that for many years, electric arc furnaces have been operated by manually controlled relay panels, which over time have been replaced by programmable logic controllers. The '438 patent teaches the integration of the PLCs and microcomputers and a method of information handling to provide on-line data collection and data communication between the programmable logic controller and the data processing microcomputer in a stand alone unit for control of the furnace, thus eliminating the need for higher level computers. While the method taught by the '438 patent has advantages, it is disadvantageous in that it does not provide the operator with substantially real-time data about the furnace operation that may be transmitted over both a secure local computer network and over a global computer network to a secure database so that the operator may make real-time decisions about the operation of the furnace.
What is desired, therefore, is a system and method for monitoring an electric arc furnace, wherein data may be collected and displayed on a local user's personal computer in substantially real-time and also transmitted to a remote secured database, where reports using the collected data stored in the remote secured database may later be prepared to evaluate the furnace's historical operation.